TLR4 and chronic obstructive pulmonary disease: It can tie to toll-like receptor 4 (TLR4) or the receptor for advanced glycation end products (RAGE) to activate JAK/STAT, PI3K/AKT, MAPK/NF-κB, and NLRP3 inflammasome pathways, thereby enhancing proinflammatory response and development of various inflammatory diseases, including autoimmune disease, chronic obstructive pulmonary disease, and cardiovascular disease (Wang et al., 2018).